efi_loader: Put fdt into convenient location

The uEFI spec doesn't dictate where the device tree should live at, but legacy 32bit ARM grub2 has some assumptions that it may stay at its place when it's already loaded by the firmware. So let's put it somewhere where Linux that comes after would happily find it - around the recommended 128MB line. Signed-off-by: Alexander Graf <agraf@suse.de> Tested-by: Andreas Färber <afaerber@suse.de>

efi_loader: Put fdt into convenient location
The uEFI spec doesn't dictate where the device tree should live at, but legacy 32bit ARM grub2 has some assumptions that it may stay at its place when it's already loaded by the firmware. So let's put it somewhere where Linux that comes after would happily find it - around the recommended 128MB line. Signed-off-by: Alexander Graf <agraf@suse.de> Tested-by: Andreas Färber <afaerber@suse.de>
Alexander Graf · Tom Rini
1 parent 36c37a8481
Showing 1 changed file with 26 additions and 4 deletions Side-by-side Diff
cmd/bootefi.c
@@ -12,7 +12,7 @@
 #include <errno.h>
 #include <libfdt.h>
 #include <libfdt_env.h>
-#include <malloc.h>
+#include <memalign.h>
 #include <asm/global_data.h>
  
 DECLARE_GLOBAL_DATA_PTR;
  
  
  
@@ -104,12 +104,34 @@
 static void *copy_fdt(void *fdt)
 {
 	u64 fdt_size = fdt_totalsize(fdt);
+	unsigned long fdt_ram_start = -1L, fdt_pages;
+	u64 new_fdt_addr;
 	void *new_fdt;
+	int i;
  
-	/* Give us 64kb breathing room */
-	fdt_size += 64 * 1024;
+        for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
+                u64 ram_start = gd->bd->bi_dram[i].start;
+                u64 ram_size = gd->bd->bi_dram[i].size;
  
-	new_fdt = malloc(fdt_size);
+		if (!ram_size)
+			continue;
+
+		if (ram_start < fdt_ram_start)
+			fdt_ram_start = ram_start;
+	}
+
+	/* Give us at least 4kb breathing room */
+	fdt_size = ALIGN(fdt_size + 4096, 4096);
+	fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
+
+	/* Safe fdt location is at 128MB */
+	new_fdt_addr = fdt_ram_start + (128 * 1024 * 1024) + fdt_size;
+	if (efi_allocate_pages(1, EFI_BOOT_SERVICES_DATA, fdt_pages,
+			       &new_fdt_addr) != EFI_SUCCESS) {
+		/* If we can't put it there, put it somewhere */
+		new_fdt_addr = (ulong)memalign(4096, fdt_size);
+	}
+	new_fdt = (void*)(ulong)new_fdt_addr;
 	memcpy(new_fdt, fdt, fdt_totalsize(fdt));
 	fdt_set_totalsize(new_fdt, fdt_size);
...	...	@@ -12,7 +12,7 @@
12	12	#include <errno.h>
13	13	#include <libfdt.h>
14	14	#include <libfdt_env.h>
15		-#include <malloc.h>
	15	+#include <memalign.h>
16	16	#include <asm/global_data.h>
17	17
18	18	DECLARE_GLOBAL_DATA_PTR;
19	19
20	20
21	21
...	...	@@ -104,12 +104,34 @@
104	104	static void copy_fdt(void fdt)
105	105	{
106	106	u64 fdt_size = fdt_totalsize(fdt);
	107	+ unsigned long fdt_ram_start = -1L, fdt_pages;
	108	+ u64 new_fdt_addr;
107	109	void *new_fdt;
	110	+ int i;
108	111
109		- /* Give us 64kb breathing room */
110		- fdt_size += 64 * 1024;
	112	+ for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
	113	+ u64 ram_start = gd->bd->bi_dram[i].start;
	114	+ u64 ram_size = gd->bd->bi_dram[i].size;
111	115
112		- new_fdt = malloc(fdt_size);
	116	+ if (!ram_size)
	117	+ continue;
	118	+
	119	+ if (ram_start < fdt_ram_start)
	120	+ fdt_ram_start = ram_start;
	121	+ }
	122	+
	123	+ /* Give us at least 4kb breathing room */
	124	+ fdt_size = ALIGN(fdt_size + 4096, 4096);
	125	+ fdt_pages = fdt_size >> EFI_PAGE_SHIFT;
	126	+
	127	+ /* Safe fdt location is at 128MB */
	128	+ new_fdt_addr = fdt_ram_start + (128 * 1024 * 1024) + fdt_size;
	129	+ if (efi_allocate_pages(1, EFI_BOOT_SERVICES_DATA, fdt_pages,
	130	+ &new_fdt_addr) != EFI_SUCCESS) {
	131	+ /* If we can't put it there, put it somewhere */
	132	+ new_fdt_addr = (ulong)memalign(4096, fdt_size);
	133	+ }
	134	+ new_fdt = (void*)(ulong)new_fdt_addr;
113	135	memcpy(new_fdt, fdt, fdt_totalsize(fdt));
114	136	fdt_set_totalsize(new_fdt, fdt_size);
115	137